Another temperature probe thread

[Wiesty]

Hey all!
So I recently bought a used 10cu ft. chest freezer which I will be using as a fermentation chamber/keg chiller. I also am running an STC-1000 temperature controller.

However, I am having troubles with keeping temperatures down. I've done plenty of reading on different methods. Currently I'm just using it as an extra beer fridge for bottles, so what I've done is tape the probe underneath some styrofoam (a piece from a styrofoam plate) to a 500ml bottle.

That being said, once the freezer shuts off, the temperature goes up probably about .5 C in about 10 minutes. Which leads me to think that the probe is still measuring more air than bottle even though its taped to a bottle with insulation.

Anyone have a better method? It can keep the temperature pretty stable, but it cant be good for my freezer to be shutting on and off 30+ times a day.

 

[mrmarcdee]

I stuck the probe into a bottle of water on the bottom of the freezer.

 

[Wiesty]

The only issue with that is once I start trying to cool 5 gallon carboys and kegs, a small bottle of water is going to cool much quicker than a 5 gallon container. Right now that would be fine since I'm only dealing with bottles, but down the road that won't work. From what i've read, taping it to the carboy is the way to go, but as I said in my first post, It doesn't seem to be taking the temperature of what its taped to very well.

 

[day_trippr]

2"x24" Velcro strap, a ~4"x3" chunk of inch-thick flexible closed cell foam scavenged from a shipping carton, with the probe trapped against the keg (or carboy - I do the same thing for fermenters). The foam provides excellent rejection of ambient effects...



I also do the same but using a larger foam patch (extra inch in both directions) in my keezer and it works very well...

Cheers!

 

[mrmarcdee]

True. But for keeping kegs at serving temperature, I would think it should even out quickly

Look-up a thermowell, basically an open-top cylinder that goes down into your fermenter. I don't think there's an option for a keg though, but maybe.

For my fermentation chamber freezer taping the probe to the plastic fermenter behind a piece of insulator (I actually use a cut off piece of a camping sleeping pad I had laying around) seems to work good for me. Maybe glass carboys insulate too well for this compared to plastic buckets?

 

[Wiesty]

I think I want to avoid the thermal-well route if i can. Just extra parts/sanitation/cleaning.

Will that packing foam work better than Styrofoam? I'm using a piece from a Styrofoam plate currently and it's not holding temps.

 

[kombat]

For fermenting, I use a thermowell and bury the probe deep at the bottom so it's measuring the temperature of the actual fermenting beer.

For serving freezers, I let the probe dangle freely in the air, away from the compressor hump. I'm hesitant to tape the probe to a keg, because if the keg it is taped to is relatively full, then the freezer could be running for quite some time before that large volume of beer comes down to the desired temperature. In the meantime, what does that mean for other kegs in the freezers, specifically ones that are nearing empty? They're going to cool much faster (less volume, lower thermal mass) and could potentially freeze. That's why I just let the probe dangle freely, measuring the air temperature in the freezer, and keeping it just above freezing.

 

[BigFloyd]

I stuck the probe into a bottle of water on the bottom of the freezer.

This is all you need do. Nuthin fancy and it works.

The water serves as a buffer and mimics the liquid temp inside the kegs. I use a spaghetti sauce jar with a hole punched in the lid and filled with water as the home for my keezer STC-1000 probe. It's worked fine for years.

 

[day_trippr]

I think I want to avoid the thermal-well route if i can. Just extra parts/sanitation/cleaning.

Will that packing foam work better than Styrofoam? I'm using a piece from a Styrofoam plate currently and it's not holding temps.

Inch for inch closed cell foam is a much better insulator than Styrofoam, and an inch thick will be much better than the 1/8" or so of your plate...

Cheers!